Abstract: An ultra high pressure waterjet cutting system which includes a valve for selectively delivering either a stream of ultra-high pressure water or alternatively, a moderately reduced but yet sufficiently high pressure to initiate cutting. The arrangement provides a convenient means for initiating cuts along the edges of workpieces and is particularly useful when encountering surfaces of brittle workpieces.

Abstract: An improved cutting head for a water jet cutting assembly utilizing water or other liquid medium at ultra high pressure, with the cutting head including an assembly with an elongated body having a central bore along its axis and including a delivery nozzle at the distal end of the assembly. Alignment of the components is maintained by incorporating a process of manufacture which utilizes the formation of a single bore extending through the body so as to both form and maintain axial alignment of the components. The arrangement is further characterized by having mating surfaces which are free of gaskets or other packing material, thereby establishing, maintaining, and preserving proper axial alignment of components.